jan 132013
Anne's Picture of the Day: The Train Wreck Cluster

January 13, 2013 The Train Wreck Cluster, a galaxy cluster in Orion Image Credit: NASA, ESA, CFHT, and M.J. Jee (University of California, Davis) The Train Wreck Cluster (Abell 520) is a galaxy cluster of 5.4 million light-years across that contains about 300 galaxies. It lies some 2.65 billion light-years away in the constellation of [continue reading]

dec 012012
‘Dark Core’ in Galaxy Cluster May Not Be So Dark After All

  Astronomers were puzzled earlier this year when NASA’s Hubble Space Telescope spotted an overabundance of dark matter in the heart of the merging galaxy cluster Abell 520. This observation was surprising because dark matter and galaxies should be anchored together, even during a collision between galaxy clusters. These composite images taken by two different [continue reading]